Palmettes of Turkey a la Bearnaise

Ranhofer writes in shorthand for a professional brigade: almost every element here is a cross-reference to another number in the book. Read it as an assembly note rather than a standalone recipe, and gather the components first.

• What the numbers stand forNo. 75 is the book's cream forcemeat, a pounded raw-poultry and cream mixture of the mousseline type; No. 723 is soubise, an onion puree bound in the usual way with rice or bechamel; No. 433 is bearnaise. No. 920 supplies the finishing instructions, so the dish cannot be executed faithfully without that page in front of you.
• Palmette moldsSmall tinned molds cut in the shape of a palm leaf, part of the nineteenth-century garnish kit and effectively unobtainable now. Small oval or boat-shaped molds, barquette tins, or buttered ramekins give the same result in a different silhouette.
• ProportionsA quarter of the forcemeat's volume in soubise is a lot of moisture for a mousseline to carry. Make the soubise thick and dry it out over heat before folding it in, or the mixture will not set when poached.
• Poaching, not boilingMousseline forcemeats want a buttered mold set in a water bath held well below the boil; a rolling boil bursts the emulsion and the palmettes turn spongy and weep butter. In a modern kitchen a bath around 170F and roughly 15-20 minutes for a small 2 oz mold, until the center is just firm to a fingertip, is a reasonable starting point.
• TurkeyUse raw breast, well chilled, with all sinew removed. Cooked turkey will not bind. Weigh the trimmed meat before pounding, since the egg white and cream are proportional to it.
• Foie grasThe slices go in the center as a surprise, so they should be cold and firm when the mold is filled and the mixture packed around them. A whole-lobe terrine slices better than a mousse, which will melt into the forcemeat.
• BearnaiseHold it warm but well short of simmering, around 130-140F; too hot and the yolks curdle, too cool and it dulls and sets. Serve it in a sauceboat as directed rather than napping the palmettes, which are meant to be seen.
• Yield and serviceA hot side dish in Ranhofer's structure, so a small portion per person alongside other courses rather than a plated main. By rough arithmetic, a pound of trimmed turkey with its cream and soubise would fill somewhere in the region of a dozen 2 oz molds.